Audio preamplifier



FIG. 1 is a perspective view of an audio preamplifier according to thepresent design;

FIG. 2 is an elevational view of the left end of the audio preamplifiershown in FIG. 1;

FIG. 3 is an elevational view of the right end of the audio preamplifiershown in FIG. 1; and,

FIG. 4 is a front elevational view of the audio preamplifier shown inFIG. 1.

The ornamental design for an audio preamplifier, as shown.